Protarchaeopteryx

[longrich@alumni.princeton.edu]

On Thursday, September 19, 2002, at 12:52 PM, Dino Guy Ralph wrote:

> Fam Jansma wrote:
>
> > Has anyone noticed the similarities in the dentition between this new 
> > genus
> > and that of Protoarchaeopteryx with the LARGE premaxillary teeth?
>
> The procumbent premaxillary teeth of _Protarcheopteryx_ are described 
> as bearing
> needle-like crowns and bulbous roots and showing minute serrations.  
> This
> description does not match the large rodent-like _Incisivosaurus_ two 
> front
> teeth and the remaining three premaxillary pairs of much smaller, more 
> slender,
> unserrated, subconical teeth.  Furthermore, the mode of preservation 
> and the
> strata do not compare either, as _Incisivosaurus_ predates 
> _Protarchaeopteryx_.
> Unfortunately, there is little overlap for comparison between the two 
> genera,
> but at present it appears safe to assume that these are distinct 
> theropods.

    Given that Protarchaeopteryx has:

-procumbent premaxillary teeth (Incisivosaurus, Caudipteryx)
-enlarged premaxillary teeth (or reduced posterior teeth depending on 
how you look at it) (Incisivosaurus)
-a skull which is relatively short for its height (Caudipteryx, 
Oviraptoridae, Incisivosaurus)
- a relatively small skull relative to the size of the animal 
(Caudipteryx, Oviraptoridae, ?Therizinosauroidea, convergent in ostrich 
dinos)
-short distal caudal segments (Caudipteryx, Oviraptoridae, probably 
Caenagnathidae, Therizinosauroidea)
-digits II and IV of pes subequal (a reversal uniting it with 
Caudipteryx, Avimimus, Oviraptoridae, Caenagnathidae)

	It looks quite likely that it is a basal member of the oviraptors, 
which is where I've usually got it in the past. It seems likely that it 
forms a grade/clade with Bunnysaurus.

-nL